docs: def handle_unqualified_relation(self, _, __, tokens: ParseResults) -> ParseResults:
          """Handle unqualified relations."""
          subject_node_dsl = self.ensure_node(tokens[SUBJECT])
          object_node_dsl = self.ensure_node(tokens[OBJECT])
          relation = tokens[RELATION]
          self.graph.add_unqualified_edge(subject_node_dsl, object_node_dsl, relation)
          return tokens